Optimization Of Wireless Charging Coils And Magnetic Shielding Research For Electric Vehicles

Traditional electric vehicle wired charging has problems such as bulky connectors,complicated operation,easy to wear and leakage,and wireless charging can solve these problems ingeniously.Therefore,research on the application of wireless charging in the field of electric vehicles has high practical value and practical significance.The coupling coil is the core component of the entire charging system,which can directly determine the transmission power and maximum transmission efficiency of the charging system.Magnetic shielding research is a key safety issue to be solved to promote the development of electric vehicle wireless charging technology.Therefore,the work of this article is of great significance to the development of electric vehicle wireless charging technology,and it can also contribute to the application and promotion of electric vehicles.Magnetic coupling resonant wireless charging has been widely used in electric vehicle wireless charging systems due to its advantages of moderate transmission distance,large transmission power,and high efficiency.Based on the transmission principle,this paper has carried out the optimization design of the coupling coil and the research of magnetic shielding.The main research work is as follows:(1)Optimized coil design.First of all,in order to obtain a better coil design scheme,the method of combining control variables and electromagnetic simulation analysis is used to analyze the wire diameter,shape,number of turns,turn spacing,size,coupling distance,etc.of the coupling mechanism,the coupling coefficient,and the coil.Influence of inductance value and AC equivalent resistance.Then,combined with theoretical analysis and simulation conclusions,optimized design of the primary and secondary coils was carried out,and a set of coil optimization design schemes for wireless charging of 6k W electric vehicles were proposed.The optimized design of the coil has been simulated for anti-offset characteristics and anti-rotation characteristics.(2)Magnetic shielding research.This paper uses ferrite and metal shielding layer for shielding.First,the method of combining control variables and electromagnetic simulation analysis is used to analyze the influence of ferrite parameters on the coupling mechanism,and a ferrite shielding scheme is proposed based on the simulation results.Then the material and thickness of the metal shielding layer were simulated and analyzed.Finally,a 2mm thick aluminum plate was used as the metal shielding layer.At the same time,the metal shielding layer was optimized according to the current density distribution on the surface of the metal shielding layer,which reduced its weight by 990 g.(3)Build the physical coil and its test platform for physical verification.In order to verify the accuracy of the design,the transmission power test,shielding effect test,and anti-offset characteristic test experiments were carried out respectively.The experimental results show that when the transmission distance is 140 mm,the charging power is 6kW,and the load is 30Ω,the transmission efficiency of the system can reach 93.33%.When the charging power reaches 6kW,the highest magnetic flux density around the charging system meets the relevant national standards.And the system has a certain degree of resistance to deflection in both the horizontal and vertical directions.